---
updatedAt: 2026-09-04T11:23:53.000Z
agentTools:
  projectIndex: https://docs.us.zip.co/llms.txt
---

# Calculate Installment Fee (formerly MFPP)

Sandbox (Testing): https://global-api.sand.au.edge.zip.co/merchant/calculate-merchant-fees

Merchants with a consumer fee (formerly MFPP) agreement can use this endpoint to determine the fee amount for a given order.This service is only available for `USD` and `CAD` currencies.

## /calculate-merchant-fees

## Useful Notes

* The state and country value correspond to the customer's shipping address.
* When the value returned in merchant\_fee\_for\_payment\_plan is $0 it means there is no fee applied to the order and this does not need to be displayed at checkout.

# OpenAPI definition

```json
{
  "openapi": "3.1.0",
  "info": {
    "title": "single-merchant-interface-smi-api",
    "version": "1.0"
  },
  "servers": [
    {
      "url": "https://global-api.prod.au.edge.zip.co/merchant"
    }
  ],
  "security": [
    {}
  ],
  "paths": {
    "/calculate-merchant-fees": {
      "post": {
        "summary": "Calculate Installment Fee (formerly MFPP)",
        "description": "Sandbox (Testing): https://global-api.sand.au.edge.zip.co/merchant/calculate-merchant-fees\n\nMerchants with a consumer fee (formerly MFPP) agreement can use this endpoint to determine the fee amount for a given order.This service is only available for `USD` and `CAD` currencies.",
        "operationId": "calculate-merchant-fees",
        "parameters": [
          {
            "name": "Authorization",
            "in": "header",
            "description": "Bearer {{API key}}",
            "required": true,
            "schema": {
              "type": "string"
            }
          },
          {
            "name": "Idempotency-Key",
            "in": "header",
            "description": "[RandomString]",
            "required": true,
            "schema": {
              "type": "string"
            }
          },
          {
            "name": "Zip-Version",
            "in": "header",
            "description": "2021-08-25",
            "required": true,
            "schema": {
              "type": "string",
              "format": "date"
            }
          }
        ],
        "requestBody": {
          "content": {
            "application/json": {
              "schema": {
                "type": "object",
                "required": [
                  "currency",
                  "customer_state",
                  "customer_country"
                ],
                "properties": {
                  "currency": {
                    "type": "string",
                    "description": "Order currency that will be applied to merchant fee plan calculation."
                  },
                  "amount": {
                    "type": "string",
                    "description": "Order amount used to calculate the merchant fee plan."
                  },
                  "customer_state": {
                    "type": "string",
                    "description": "Customer state derived from the customer's shipping address"
                  },
                  "customer_country": {
                    "type": "string",
                    "description": "Customer country derived from the customer's shipping address"
                  }
                }
              }
            }
          }
        },
        "responses": {
          "200": {
            "description": "200",
            "content": {
              "application/json": {
                "examples": {
                  "Result": {
                    "value": "{\n  \"adjusted_order_amount\": 64,\n  \"currency\": \"USD\",\n  \"merchant_fee_for_payment_plan\": 4\n}"
                  }
                },
                "schema": {
                  "type": "object",
                  "properties": {
                    "adjusted_order_amount": {
                      "type": "integer",
                      "example": 64,
                      "default": 0
                    },
                    "currency": {
                      "type": "string",
                      "example": "USD"
                    },
                    "merchant_fee_for_payment_plan": {
                      "type": "integer",
                      "example": 4,
                      "default": 0
                    }
                  }
                }
              }
            }
          }
        },
        "deprecated": false
      }
    }
  },
  "x-readme": {
    "headers": [],
    "explorer-enabled": false,
    "proxy-enabled": true
  },
  "x-readme-fauxas": true
}
```